Oxidation of meteor material

[mvida]

Hello!

I'm new to phreeq-c, and had a question about oxidation of certain species. I'm trying to model the oxidation of reducing meteoric impactor material in the Archean earth. I have an equilibrium block for ancient crust, a block for the atmosphere, and a block for surface water that I want the impactor material to interact with (keeping it basic for now). I'm trying to follow example 9 to do this. For brevity I'll paraphrase how my code looks, but can provide a detailed example if needed:

Code: [Select]

SOLUTION_MASTER_SPECIES
*copy + pasted from example 9*

SOLUTION_SPECIES
*copy + pasted from example 9*

PHASES
*enstatite chondrite impactor material*
END

SOLUTION 1
*surface water*

EQUILIBRIUM PHASES 1
*crustal material*

EQUILIBRIUM PHASES 2
*atmosphere*
END

RATES
*copy + pasted from example 9*

KINETICS 1
*copy + pasted from example 9*

INCREMENTAL_REACTIONS true

SELECTED_OUTPUT
*file info*
USER_PUNCH
        -headings Days  Fe(2)  Fe(3)  pH  si_impactormaterial
  10 PUNCH SIM_TIME / 3600 / 24, TOT("Fe_di")*1e6, TOT("Fe_tri")*1e6, -LA("H+"), \
           SI([impactor material])
USER_GRAPH
*copy + pasted from example 9*


I just wanted to see if this is the correct approach for something like this. Thank you!

[dlparkhurst]

If you have reduced minerals in EQUILIBRIUM_PHASES, and you add oxygen, then the reduced minerals will dissolve.

I am not going to deem your approach right or wrong. You will have to work that our yourself.

Note that in reaction calculations, you only get at most one of each type of reactant--so, only one EQUILIBRIUM_PHASE, but it can contain multiple minerals and(or) gases.

Here is an example where pyrite is oxidized by addition of oxygen. Pyrite dissolves and consumes all of the oxygen.

Code: [Select]

SOLUTION 1
END
EQUILIBRIUM_PHASES 1
Pyrite 0 1
END
REACTION 1
O2 1
1e-3 moles
END
USE solution 1
USE equilibrium_phases 1
USE reaction 1
END